Method for forming inside tampon applicator tubes

ABSTRACT

THIN-WALLED PAPER TUBE BLANKS ARE SUPPLIED BY A FEEDER MECHANISM TO A TUBE ORIENTING AND LOADING STATION WHERE THEY ARE INDIVIDUALLY AND SUCCESSIVELY LOADED IN RESPECTIVE ONES OF A PLURALITY OF COLLETS RESILIENTLY MOUNTED ON AN INDEXABLE TURNTABLE TO BE ACTED ON SUBSTANTIALLY SIMULTANEOUSLY BY A SET OF FORMING ELEMENTS CARRIED ON A MEMBER RECIPROCALLY MOUNTED TO ADVANCE AND RETRACT TO AND FROM TUBE ENGAGING POSITIONS DURING DWELL PERIODS OF THE TURNTABLE. THE TUBES ARE GENTLY HELD BY THE COLLETS WITH A VERY LIGHT FORCE FITTING ACTION WHICH PREVENTS DISTORTIONS TO THE TUBES DURING THE FORMING OPERATIONS. ONE END OF THE TUBE IS CRIMPED AND FOLDED INWARDLY IN THE GENERAL SHAPE OF A TRUNCATED CONE AND THE OTHER END IS FORMED   WITH AN INWARDLY ROLLED FLANGE. THE RECIPROCATING MEMBER ALSO CARRIES AN ELEMENT FOR DISCHARGING THE TUBES FROM THEIR RESPECTIVE COLLETS AT AN UNLOADING STATION.

P 23, 1971 c. w. JOHNSON 3,608,441

METHOD FOR FORMING INSIDE TAHPON APPLICATOR TUBES Filed Feb. 3. 1969 6 Sheets-Sheet 1 M 3 1 3 T, i [E] a\ kQ 5 \3 E & N 3

ll l'" Sept. 28,-1971 c. w. JOHNSON METHOD FOR FORMING INSIDE TAMPON APPLICATO R TUBES Filed Feb. s. 1969 6 Sheets-Sheet 2 ran 22; we; (fay/rm fl/ WWI/Mam p 28, 1971 c. w. JOHNSON 3,608,441

' METHOD FOR FORMING INSIDE TAMPON APPLICAI'OR TUBES Filed Feb. 5, 1969 6 Sheets-Sheet 5 4 WW W z W i f z w W M W Sep 1971 c. w. JOHNSON 3,603,441

METHOD FOR FORMING INSIDE TAMPON APPLICATOR TUBES Filed Feb. 3, 1969 6 Sheets-Sheet 6 United States Patent 3,608,441 METHOD FOR FORMING INSIDE TAMPON APPLICATOR TUBES Carl W. Johnson, N eenah, Wis., assignor to Kimberly- Clark Corporation, Neenah, Wis. Filed Feb. 3, 1969, Ser. No. 795,904 Int. Cl. B31f 7/00; B31b 1/44, 1/94 US. Cl. 9394 FC Claims ABSTRACT OF THE DISCLOSURE Thin-walled paper tube blanks are supplied by a feeder mechanism to a tube orienting and loading station Where they are individually and successively loaded in respective ones of a plurality of collets resiliently mounted on an indexable turntable to be acted on substantially simultaneously by a set of forming elements carried on a member reciprocally mounted to advance and retract to and from tube engaging positions during dwell periods of the turntable. The tubes are gently held by the collets with a very light force fitting action which prevents distortions to the tubes during the forming operations. One end of the tube is crimped and folded inwardly in the general shape of a truncated cone and the other end is formed with an inwardly rolled flange. The reciprocating member also carries an element for discharging the tubes from their respective collets at an unloading station.

BACKGROUND OF THE INVENTION The present invention relates generally to tampon applicator devices and more particularly concerns an improved method and apparatus for forming the inside tampon ejecting tube.

In copending application Ser. No. 690,001, filed Dec. 12, 1967, now U.S. Pat. No. 3,568,577, and in which I am one of the joint applicants there is disclosed a method and apparatus for forming tampon applicator tubes in the general shape of those disclosed in US. Patents No. 3,204,635 and No. 3,358,354 wherein the forward end of the inside tampon ejecting tube is crimped and folded into the general shape of a truncated cone. In copending application Ser. No. 742,808, filed July 5, 1968, now U.S. Patent No. 3,505,931, and in which I am one of the joint applicants there is disclosed a subsequent method and additional apparatus for forming an inwardly-directed flange on the other end of such an inside tampon ejecting tube to eliminate the sharp edge and reduce the unit pressure otherwise encountered with the use of thin-Walled paper tube stock.

As disclosed in the first above-mentioned application precut blanks of thin-walled paper tube stock are successively fed by a vibratory feeder to a horizontal loading station where they are individually loaded on respective ones of a plurality of support punches resiliently mounted on an intermittently indexable turret. The punches have a necked down forward end and cooperate vw'th successive crimping and forming dies located in a die plate which reciprocata into and out of engagement with the tubes on the support punches during the dwell periods between indexing movements of the turret. The tubes are then removed from the punches by engagement with the paddles of a rotating paddle wheel which propel the tube into a conveyor for delivery to subsequent forming or fabricating apparatus.

The latter copending application mentioned above discloses a separate method and apparatus for forming an inwardly directed flange on the rear end of an inside tampon ejecting tube. The method and apparatus there disclosed requires that the forward end of the tube first is formed on apparatus as disclosed in the former applica- 3,608,441 Patented Sept. 28, 1971 tion, removed from its punch, conveyed to the flanging apparatus, loaded in the tube supporting bore of another turret which is indexed first to a flange forming station and then to an unloading station.

SUMMARY OF THE INVENTION It is the primary aim of the present invention to provide a unified method and apparatus which forms both the forward and rear ends of an inside tampon ejecting tube without necessitating unloading the tube from. one machine and transporting to and loading in a second machine.

A more particular object is to provide a novel tube holding arrangement which permits successive forming operations to be made on opposite ends of the tube without removal of the tube from the holder.

It is also an object to provide a tube orienting and loading mechanism which gently but accurately inserts the tubes in the holding fixtures. A further object is to provide a positive unloading mechanism which operates in sequence with the tube forming apparatus.

These and other objects and advantages of the invention will become more readily apparent upon reading the following detailed description and upon reference to the drawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation, with certain internal portions shown in dash lines, of the tube forming apparatus of the present invention;

FIG. 2 is a plan view of the apparatus shown in FIG. 1;

FIG. 3 is a side elevation, partially in section, of a preferred form of tampon applicator;

FIG. 4 is a partial perspective of the vibratory feeder shown in FIG. 1;

FIG. 5 is an enlarged fragmentary section of the tube loading station of the apparatus taken substantially along line 5-5 in FIG. 2;

FIG. 6 is an enlarged fragmentary section, similar to FIG. 5, illustrating a tube being inserted in its holding device;

FIG. 7 is a further enlarged fragmentary section of one of the tube holders;

FIG. 8 is an enlarged section of the tube crimping station taken substantially along line 88 in FIG. 2;

FIG. 9 is a side elevation of a tube, the forward end of which has been crimped;

FIG. 10 is an enlarged fragmentary section of the tube forming station taken substantially along line 10-10 in FIG. 2;

FIG. 11 is a side elevation of a tube the forward end of which has been formed with a frusto-conical shape;

FIG. 12 is an enlarged fragmentary section of the tube 'flanging station taken substantially along line 1212 in FIG. 2;

FIG. 13 is an enlarged fragmentary section of the tube unload station taken substantially along line 13-13 in FIG. 2; and,

FIG. 14 is a fragmentary plan view of the crimping die as seen from line 14-44 in FIG. 8.

DETAILED DESCRIPTION OF THE INVENTION The method and apparatus of the present invention are particularly suited for fabricating tampon applicator devices 10 as depicted in FIG. 3 of the drawings. It will be understood, however, that the invention has broader utility, being equally applicable to hygienic medium devices such as suppository applicators and the like, and it is not intended to limit the invention to the specific examples given.

By way of example, the device includes an elongated, outer tube 12 which has a relatively thin wall and is preferably in the form of a laminated tubular structure of the kind disclosed in detail in copending application Ser. No. 726,522 filed on May 3, 1968 and entitled Laminated Tube Structure and Method and Apparatus for Manufacturing Same. Because of its thin wall, the tube 12 may be subject to deformation when grasped by the fingers during use of the device. The tube 12 is therefore provided with a reinforcing ring 14 mounted about the exterior surface of the tube flush with the rear extremity thereof. The ring 14 serves not only to reinforce the external tube 12, but provides a secure, nonslip gripping means and also facilitates orientation of the applicator to properly direct the ejection of the tampon into the vagina. The tube 12 also includes a tapered forward tip 16 which permits easy and rapid insertion without discomfort or irritation to the user. The tapered tip 16 may be formed, for example, by folding the forward end of a tube blank into a plurality of tightly abutting pleats in the manner disclosed in U.S.

Patent Nos. 3,204,635 and 3,358,354 and copending application Ser. No. 690,001 referenced earlier; but a preferred and improved method and apparatus for forming outside tampon applicator tubes is disclosed in copending application Ser. No. 795,825 of the same title filed Feb. 3, 1969.

The device 10 also includes a tampon 18 housed in the forward portion of the external tube 12. The forward end 20 of the tampon 18 is tapered to substantially conform to the configuration of the interior of the tapered tip 16. A drawstring 22. is connected to the rear extremity of the tampon 18 and extends rearwardly therefrom.

The applicator 10 further includes tampon-ejecting means, in the form of an inner tube 24 slideably received, in telescoping relation, within the rear portion of the tube 12. The inner tube 24 is provided with a pleated, reduced diameter forward section 26 which may be formed in a manner similar to that mentioned in connection with the tapered tip 16 of the outer tube 12. The reduced diameter forward section 26 eliminates any frictional interference which might otherwise result from burrs or other projections riding in contact with the interior surface of the tube 12. It also precludes any tendency on the part of the tampon material to catch or bind between the adjacent, relatively slideable surfaces of the inner and outer tubes. The inner tube 24 also has an inwardlydirected flange 28 on the rear extremity to provide a more comfortable surface against which the finger of the user is pressed. The flange also serves to strengthen the tube by increasing its resistance to deformation under finger pressure and a substantially constant, low level of frictional drag between inner and outer tubes is thus maintained. An added advantage of the flanges is that it guards against the possibility of the users finger sliding inside the tube, in addition to the other purposes of which have already been discussed.

The tube 24 may be constructed from any suitable material; as explained in greater detail in the aforementioned copending application Ser. No. 726,522 entitled Laminated Tube Structure and Method and Apparatus for Manufacturing Same, it may comprise a laminated structure similar to that of the external tube 12.

Previously, the reduced diameter forward section 26 of the tube 24 was fabricated with the methods and apparatus described in the aforementioned application Ser. No. 690,001 by placing a length of tube stock over a closely fitting punch or male die in the form of an elongated shaft having a forward end incorporating the desired reduced diameter configuration. Appropriately configured female folding dies were then brought into successive engagement with the end of the tube stock and cooperate with the male die to provide the final, reduced diameter shape. While the use of the described die sets greatly facilitates the fabrication of the tubes on an economical, production basis; this arrangement precludes the formation of the rear flange 28 until after completion of the forward section and makes inconvenient the use of devices engaging the interior wall surface of the inner tube.

Thus, in the past to perform this latter operation it was necessary to remove the tube from the male die of the forward end forming machine and to convey and load it in the female die of a flange forming apparatus as disclosed in copending application Ser. No. 742,808 filed July 5, 1968.

In accordance with one aspect of the present invention I have found that the inner tube 24 can be gently but positively held by supporting means which permits a single apparatus to successively form the reduced forward section 26 and the rear flange 28 of the tube 24 without removing the tube from the apparatus. As a result, manipulation of the tube, including the formerly required unloading, conveying and loading steps between forming operations are eliminated with a consequent increase in production speed and reduction in tube deformation and damage.

Referring now to FIGS. 1 and 2, the apparatus of the present invention includes a tube blank feeder 40 and a tube forming unit 42. A first conduit 44 is provided for transporting cylindrical tube blanks 45 from the feeder unit 40 to the forming unit 42 and the formed tubes are discharged from the forming unit through conduit 46 or reject conduit 47 depending on whether any defects are noted in the tube by visual inspection. The selection of conduit 46 or conduit 47 is accomplished by a reject flapper mechanism 48 controlled by the operator.

The feeding unit 40 includes a supporting stand 52 on which a-vibratory bowl feeder assembly 54 is mounted. The assembly 54 may be a commercially available unit of the type sold, for example, by the Syntron Company, Hover City, Pa. The bowl 55 in such an assembly 54 is formed with a spirally inclined track 56 which terminates at an exit opening 57 along the upper rim of the bowl. When actuated, the assembly 54 vibrates the bowl 55 in such a manner that the cylindrical tube blanks 45 are induced to travel upwardly in generally end-to-end relation along the spiral track 56. The bowl is further provided with a pair of wedges 58 and 59 to assure that only a single line of tube blanks travel to the outlet openings 57 (see FIG. 4). Thus, the wedge 58 is disposed at a height of about one tube diameter above the spiral track 56 to peel off any tube layer above the lowest layer. The wedge 59 is disposed so that it peels off all adjacent rows of tube blanks except one which is permitted to advance up the track 56.

The forming unit 42 includes a stand 61 which encloses a drive assembly 62 coupled to a forming assembly 63 supported on the stand. The forming assembly 63 includes a rotatable turntable 64 and a die holding plate 65- reciprocally mounted by bushings 67 and support arms 66 on a plurality of vertical guides 68. The plate 65 is reciprocated by an operating rod 70 the lower end of which is connected to a crank mechanism 71 driven by a motor 72 through a chain drive 73 and 74 and a gear reduction unit 75. The upper end of the operating rod 65 is preferably connected to the plate 70 with large overload spring 76 interposed between the plate and a large washer 77 held on the rod with a nut 78. Thus, if any of the die elements mounted on the plate 65 are not properly registered with the turntable 64 as the plate descends the spring 76 cushions the impact.

Rotation of the turntable is also accomplished through the drive motor 72, chain drives 73, 74 and gear reduction unit 75. However, in this instance a cam operated dwell unit 80 is interposed between the drive chain 74 and the turntable 64. The dwell unit 80 is of conventional construction and is preferably such that the turntable is rotated only as the crank 71 passes through its upper of rotational movement. Conversely, during the lower 240 of crank rotation the turntable is maintained in a dwell position. The final drive between the dwell unit 80 and the turntable may comprise a ring gear (not shown) driven by a gear on the output of the dwell unit with a gear ratio such that the turntable is indexed 15 for every revolution of the crank 71.

In accordance with the present invention the tube blanks are fed from the feeding unit 40 through the delivery conduit 44 to a tube orienting and loading station 100a in the forming apparatus 42. As shown in FIG. 4 one end of the conduit 44 is held by a bracket 102 mounted on the bowl 55 so as to receive tube blanks 45 through the exit opening 57. The other end of the conduit 44 is fitted into an enlarged bore 104 formed in a tube receiving block 105 supported by a pedestal 106 above and outboard of the turntable 64 (see FIG. The block 105 also includes a smaller bore 107 dimensioned to receive the tube blanks 45 from the conduit 44.

As each tube 45 passes horizontally through the bore 107 its forward end is projected over a lip 110 and urged against a vertical surface 111 formed in the block facing the bore 107. The tube is held in cantilevered fashion by a weight 112 vertically slidable in a slot 113 formed in the block 105 in a position such that the weight engages the upper rear surface of the tube. The tube engaging surface of the weight is preferably formed with a generally arcuate shape as at 114.

Vertical orientation of the tube is accomplished by a slide element 115 secured by a bracket 116 to the die holder 65 for vertically reciprocating movement in a guide channel 117 formed in the block 105. At its lower end the slide element 115 is provided with a tube engaging tongue 118 which has a groove 119 formed in its lower face adapted to engage the upper surface of the projecting end of respective ones of the tube blanks 45. As the slide element 115 descends with the die holder 65 the projecting end of the tube is swung downwardly through a substantially vertical are along arcuate guide surface '111a as is illustrated in broken lines in FIG. 5. At the same time the rear end portion of the tube raises the weight 112. in its slot 113 as the tube swings around the fulcrum afforded by lip 110. The rear end of the tube then swings out of engagement with the weight 112 which descends in its slot 113 into engagement with the upper surface of the next succeeding tube blank 45.

The downward swinging movement of the tube is arrested by cooperating vertical guide surfaces 120 and 121 formed in the block 105 and slide element 115, respectively. This orients the tube in vertical alignment for insertion into the bore 124 of a tube holding collet '125 carried by the turntable 64. Further downward movement of the slide element 115 causes a shoulder 1-26 to engage the upstanding rear end of the tube 45 and push the tube into the bore 124 of the collet 125 (see FIG. 6). At the same time the forward motion of the tubes in conduit 44 causes the forward end of the next succeeding tube to engage the vertical face 127 of the slide element 115.

Pursuant to a further aspect of the invention each tube blank 45 is gently but snugly held in a light force fit relation within the bore 124 of a respective one of the collets 125 which are spaced around the periphery of the turntable at intervals in the illustrated tube forming apparatus 42. To this end, the bore 124 of each collet 125 is formed with a tapered entrance end 128 tohelp guide the tube into the bore 124 and the collet 125 is provided with split lower end 129 of slightly less diameter than the bore 124 to gently engage the outer surface of the tube with a light force fit.

As the crank 71 completes its revolution the operating rod 70 raises the die holder 65 and with it the slide element 115 out of engagement with the tube 45 just inserted in the collet 125 located at the loading station 100a. During the 60 of crank rotation both proceeding and succeeding the top dead center position, in other words the top one third of rotational crank movement, the turntable 64 is rotatably indexed 15 forward (in a clockwise direction as seen in FIG. 2). This sequence of reciprocating movement of the die plate 65 and intermittent rotation of the turntable 64 permits the slide element and the other forming dies, discussed below, to be raised out of engagement with the tube blanks 45 from a period well before the beginning of the rotatable indexing movement of the turntable 64 until well after the termination of such indexing movement. This not only insures that the reciprocating elements will not foul the end of the tube blanks as they are indexed to their next position but also precludes the reciprocating elements from striking the turntable prior to the completion of its indexing movement. However, as mentioned above, in the event of an inadvertent failure of the timing sequence to maintain the reciprocating elements in proper registry with the tubes in the collet holders 125, the overload spring 76 will act to cushion the major portion of the descending weight of the die plate 65.

In the illustrated forming apparatus 42- the turntable 64 is provided with 24 collet, holder assemblies 125, thus setting the indexing movement of the turntable at 15 A lesser or greater number of collets could, of course, be provided in which case the indexing movement of the turntable would also be desirably changed to a corresponding fraction of a full revolution.

From the loading station 100a, each tube is indexed through a plurality of idle stations and then to a crimping station 100b. At the crimping station the forward end of the tube 45 is crimped or pleated in the configuration illustrated in FIG. 9 by the reciprocating action of a crimping punch assembly 130 which forces the forward end of the tube axially into a female crimping die 131. As shown in FIG. 8, the punch assembly 130 includes a rigid punch portion 132 secured to the die plate 65 for reciprocation therewith and provided with a tapered pilot end 133 adapted to enter the upstanding end of the tube located at the crimping station 10%. A shoulder 134 on the punch 132 engages the upper end of the tube and forces the tube down into the crimping die 131.

The crimping die 131 is formed with a plurality of radially disposed downwardly converging crimping ribs 135 (see FIG. 14) which serve to crimp and pleat the forward end of the tube. The die 131 is located in a bore 136 of pedestal 137 below the turntable 65 and is held at the proper height by a set screw 138 which engages a support bushing 139. To facilitate the crimping action the forward end of the tube also engages a plunger 140 slidably mounted within a central opening of the die 131 and a bore 141 in the bushing 139. The plunger is biased upwardly by a compression spring 142 located in a bore 143 of the pedestal and bearing against a collar 144 pinned to the lower end of the plunger. The amount of compression force exerted by the spring 142 may be adjustably set by rotation of an adjusting screw 145 threaded in the lower end of the pedestal 137.

In keeping with a further aspect of the invention, the forward end of the tube 45 is withdrawn from the crimping die 131 by the upward force afforded by a spring biased between a flange 151 on the upper end of a floating inner sleeve 152 and a shoulder 153 on the lower end of a mounting collar 154 of the collet 125. As seen in FIG. 7, the mounting collar of the collet is secured to the turntable 64 by means of cap screws 155. The upward movement of the sleeve 152 is limited by a set screw 156 threaded into the mounting collar and received in a limited length slot 157 in the lower portion of the sleeve. The downward movement of the sleeve 152 is limited by engagement of the flange 151 with a shoulder 158 formed in the stepped bore 159 of the mounting collar in which the sleeve reciprocates.

Returning again to FIG. 8 it will be seen that the crimping punch assembly 130 includes a sleeve 160 slidably mounted on the punch 132 and adapted to engage and force the collet sleeve 152 downwardly as the punch 132 forces the tube down into crimping die 131. A compression spring 161 surrounding the sleeve 160 and punch 132 and abutting respective flanges 162 and 163 thereon serves to normally locate the sleeve on the punch in readiness for engagement with the collet sleeve 152.

Following the crimping operation each tube is indexed to a forming station 1000 where the forward end of the tube is pressed into the generally frusto-conical shape shown in FIG. 11 by a forming punch assembly 170 and a cooperating female forming die 171. As shown in FIG. the forming punch assembly is generally similar to the crimping punch assembly 130 in FIG. 8 except that the former includes a male die punch 172 with a frustoconical forming end 173 rather than the simple pilot end 133 of the latter. The female forming die 171, of course, is also of generally frusto-conical cross sectional shape and is positioned to cooperate with the male punch 172 to form the forward end of the tube with the preferred final shape for the reasons discussed above and disclosed in the previously mentioned patents and copending applications. Except as noted above the same reference numerals have been used to identify parts of the forming punch assembly 170 and forming die support which correspond to similar parts of the crimping punch and die assemblies.

In a forming machine designed for high speed operation it will be appreciated that proper balancing of forces becomes quite important. For this reason the preferred form of the apparatus 63 is provided with a second forming station 100d located diametrically opposite forming station 1000 described above and identical to it in all material respects. Thus, it will be noted that section lines 10-10 have been indicated at two opposed locations 1000 and 100d in FIG. 2.

Another important feature of the method and apparatus of the present invention is the provision of means for inwardly fianging the rear end of the tube blank 45 as at 28 of the inner tube 24 shown in FIG. 3 without necessitating removal of the tube blank from its holding collet 125. Indeed, after completion of the second forming operation at station 100a the tube is indexed to a rear end fianging station 100e. An intermediate dwell station as indicated in FIG. 2 may be provided, but this is not necessary since, if space permitted, the tube could be indexed directly from the forming station 100d to the fianging station 100e.

As shown in FIG. 12, the roll fianging apparatus 180 follows the same principles disclosed in the above mentioned copending application Ser. No. 742,808 in that a pair of freely rotatable rollers 181 are brought into engagement with the rear end of the tube and orbited about the periphery thereof by a drive motor 182. However, the method of holding the tube 45 during this fianging operation differs significantly from that disclosed in the above noted application in that here the tube is resiliently held by the collet 125 and axial movement of the tube under the force applied by the rollers 181 is resisted solely at the previously formed forward end of the tube by an anvil-headed bolt 183 adjustably positioned in a mounting pedestal 184 and locked in place by a nut 18 5. Since the inner collet sleeve 152 is urged downward by the rollers 181 only slightly, the bolt head 183 is preferably flat to insure that the forward end of the tube does not hang-up on the bolt during the next indexing movement of the turntable 64.

The motor 182 of the roll fianging apparatus 180 is mounted on a bracket .187, the die plate 65 and the motor drive shaft 188 is coupled to a shaft 189 journalled by bearings 190 within a housing 191 secured to another bracket 192 depending from the die plate. A coupling 193 interconnects the motor drive shaft 194 with the upper end of the shaft 189 the lower end of which carries a cross shaft 195 that journals the rollers 181.

As the rollers 181 are axially impinged against and orbitally rotated about the periphery of the rear end of the tube, the inner collet sleeve 152 is urged downwardly and the forward end of the tube 45 abuts the bolt head 183. Further downward movement of the rollers urges the sleeve 152 down and inwardly flanges the rear end of the tube much in the same manner as disclosed in the above mentioned application. At the completion of the fianging operation the biased collet sleeve 152 lifts the tube out of engagement with the head of the support bolt 183 to permit indexing of the tube, without damage, to the unloading station When the tube is indexed to the unloading station 100 and the die plate 65 again descends, a blunt punch 200 mounted by a bracket 201 carried on the die plate 65 engages the inwardly-flanged rear end of the tube and slidably forces the tube out of the inner collet sleeve 152 (see FIG. 13). As the tube drops from the collet it falls into a downwardly inclined groove 203 formed in a discharge block 204 and down an inclined ramp 205 into the mouth 206 of a discharge tube leading to the reject flapper unit 48 which controls passage of the tube into either conduit 46 or reject conduit 47 as described above.

Inasmuch as the operation of the forming apparatus 42 has been described along with the detailed description of its component parts further elaboration on the methods of operation should not be required. Sufiice it to say that the forming apparatus 42 provides means for automatically and accurately orienting and inserting successive tube blanks 45 in respective ones of a plurality of resiliently mounted collet sleeves 152 which gently grip the tubes with a light force fit action. The tubes are then indexed through successive forming operations including the crimping and forming of the forward end of the tubes with a generally frusto-conical shape and the inwardly fianging of the rear end of the tube. During each of these forming operations the biased collet sleeve is urged downwardly with the tube and on completion of the respective forming operation the collet sleeve 152 retracts the forward end of the tube from the stationary female die or abutting structure. Finally the tube is stripped from the collet sleeve at an unloading station by the reciprocal action of a blunt discharge punch 200 and the tube falls into an inclined groove and into the mouth of a discharge tube.

I claim as my invention:

1. The method of shaping the ends of thin-walled tubes comprising;

inserting one of the tubes within the bore of a slidable collet which is normally biased in a first position and the bore of which is dimensioned to gently hold the tube with a light force-fit action,

indexing the tube and collet into alignment with a male punch and a female die for forming one end of the tube, reciprocating the punch relative to the die so as to engage the other end of the tube and to force the one end into the die while also sliding the collet against the force exerted by the normal bias and t en,

retracting the punch relative to the die and the tube while also permitting the biasing force to return the collet to its first position and thereby withdraw the formed end of the tube from the die.

2. The method defined in claim -1 wherein a plurality of slidable collets are carried by an indexable turntable and including the initial steps of feeding successive tubes in abutting end-to-end relation along a horizontal path and aligning each tube with the bore of a respective one of said slidable collets as they each dwell at a loading station.

3. The method defined in claim 2 wherein the bores in the collets are vertically disposed and the step of aligning the tubes therewith includes engaging the forward portion of each tube with a vertically reciprocating element to swing the forward end of each tube through a substantially vertical arc and into alignment with one of the collet bores.

4. The method defined in claim 3 wherein the vertically reciprocating element is reciprocated in unison with the reciprocating punch and the inserting step further includes engaging the rear end of each tube with a shoulder on the vertically reciprocating element to force the tube into the collet bore.

5. The method defined in claim 1 including the additional steps of indexing the tube and collet successively into alignment with additional punch and die arrangements including a crimping die in advance of a forming die and reciprocating the additional punch and die arrangements relative to one another to first crimp and then shape the forward end of the tube.

6. The method defined in claim 1 including the further steps of again indexing the tube and collet into alignment with the center of a flat anvil surface disposed adjacent the previously formed forward end of the tube and in alignment with the orbital axis about which a pair of rollers rotate and reciprocating the rollers relative to the anvil so as to engage the other end of the tube and form an inwardly-directed flange thereon while the forward end of the tube bears against the anvil surface.

7. The method defined in claim 1 including the further steps of again indexing the tube and collet to an unload station and reciprocating a stripping punch into engagement with the tube to push the tube vertically out of the collet.

8. The method defined in claim 1 wherein a plurality of slidable collets are carried by an indexable turntable and including the additional steps of;

feeding the tubes in axially aligned and abutting relation along a horizontal path to a loading station,

urging the forward end of the leading tube against a fixed substantially vertical surface and holding the major forward portion of the tube in cantilevered relation with a vertically slidable weight engageable with the upper surface of the trailing end of the tube, and

engaging the upper surface of the cantilevered portion of the tube with a downwardly moving slide element to swing said forward end out of engagement with said substantially vertical surface and through a downwardly directed are into vertical alignment with 10 the bore of one of the collets while causing said trailing end of the tube to raise said weight and swing out of engagement therewith.

9. The method defined in claim 8 including the additional step of arresting said downwardly swinging movement of said forward end by impinging it against another substantially vertical surface located below and parallel to said other vertical surface and on the opposite side of the collet bore.

10. The method defined in claim 8 including the further step of engaging the trailing end of said tube with a horizontal shoulder on said slide element and forcing said vertically aligned tube downwardly into engagement with the collet bore.

References Cited UNITED STATES PATENTS 2,109,505 3/1938 Rue 9394OFC 2,288,966 7/1942 Blanchet 9394OFC 2,440,391 4/ 1948 Bogoslowsky 9336.8 2,563,633 8/1951 Amberg 9379X 2,639,646 5/1953 Thompson 93365 2,737,090 3/1956 Nordquist 9359ES 2,737,332 3/1956 Amberg 9379X 2,837,980 6/1958 Brewer 9359ES 3,358,354 12/1967 Voss 29-419 3,430,410 3/1969 Heisler 9393HT 3,466,842 9/1969 Bailey 9393HT 3,491,633 1/1970 White 9393HT 2,053,299 9/1936 Reed 9336MM 3,505,931 4/1970 Voss 9336R 2,054,024 9/1936 Pye 9359PL 3,464,327 9/ 1969 Yovanovich 9359PL FOREIGN PATENTS 188,227 3/1964 Sweden 9336.8

WAYNE A. MORSE, 111., Primary Examiner US. Cl. X.R.

9336.5, 39 CO, 59 ES, 59 PL, 93 HT 

